Improving Object Imaging With Sea Glinted Background Using Polarization Method: Analysis and Operator Survey

Abstract

When observing sea water, a specular reflection of a light source may appear in the form of bright points of light that come and go. These bright points of light, called glints, blend together to form a smooth path of glittering light when viewed from a distance. For detection and observation systems, glints may produce severe saturation in different parts of the image, generating blinding glares and increased fatigue for the observer, which causes hardships in marine remote sensing and target detection. In our work, we have advanced the state-of-the-art analysis of the polarization-based approach to glint reduction and target imaging for a modern remote sensing system by adding external linear polarizers to an observation system on the Red Sea shore. The results of our experiments are presented, analyzed, and discussed, qualitatively and quantitatively, using image processing tools. We performed: 1) an analysis of the RGB histograms of the overall image, the sea and the background; 2) an auto segmentation using the MATLAB image processing toolbox on colored and grayscale images; and 3) saturated frame pixel analysis. An operator survey was added to validate the proposed method. The results show that a polarizer at the optimal angle can help reduce the glints, and, as a result, leads to image enhancement for oceanic applications in general, and for oceanic detection and remote sensing systems in particular.